Jet fighter aircraft : five 'generations' later, and still counting

Use of the term ‘aircraft generations’ first appeared in the early 1990s and its concept applies to jet fighter aircraft exclusively. Although use of this terminology remains unofficial and imprecise, it is generally accepted that Dr. Richard Hallion was one of the first to coin use of the term when describing the leap-frogging improvements in jet fighter design and development. In this context, ‘generations’ denotes the ‘features’ of jet fighter aircraft. Some writers have described these generations slightly differently over time, including Hallion himself and this has generally led to confusion in how jet fighter aircraft generations should be categorized. One writer even questions the origin and timing of the use of the terms fighter ‘generations’, stating the first use of this terminology actually originated in Russia during the mid-1990s, when Russian officials there used the term during planning stages of a Russian equivalent to the US Joint Strike Fighter.